The present invention relates to an arrangement for optical measuring of concentration of substances.
In biological objects of measurement, frequently concentration of fractions of particles must be determined and the determination is predominantly performed in aqueous solutions. In known methods, the distorting influence of particles which are not interesting for measurement or the distorting influence of water upon the particles to be measured is very high. In optical measurements frequently the measuring radiation is distorted so that quantitive measurements are questionable. While the particles which are optically measurable by luminescent or absorption indicators can be measured, for example in accordance with the DE-PS 2,508,637, by optodes or optical indicators containing indicator space, the optical measurement of infrared active particles or particles for which no indicators are available is problematic because of the above-mentioned circumstances.